Sothius' Home of Ancient Microcomputers

ATARI 260ST

ATARI 260ST logo (6 KBytes)

ATARI 260ST

ATARI 260ST (64 KBytes)

ATARI 260ST with SC1224 color monitor and STM1 mouse
(picture copyright by M.A.Grundke)

Specifications

Name ATARI 260ST

Made by ATARI Corp.
Sunnyvale, California

Released
1986
first ST-prototypes were shown on CES 1985 (i.e. a 130ST with 128KB RAM)
first ST officially sold was the 520ST (in Summer 1985)

Serial-No. A1 4007726

Board-info
ATARI® C070243 Rev.C
also see the board overview

CPU Motorola MC68000
C025915-38 'GLUE'
although having 16 bit data/ 24 bit address bus, the MC68000 internally processes 32 bits, thus the 'ST' (meaning 'sixteen thirtytwo')
GLUE is the ST-architecture's 'Control logic' and coordinates all of its components

Speed 8 MHz

RAM C025912-38 MMU
512 KBytes:
16 pcs. Texas Instruments TMS4256 (256Kx1)
see 'Misc' for why it's nevertheless called 260ST
expandable to 4096 KBytes, which is also MMU-limit

ROM/ Native OS PAL TOS 1.0 ('The Operating System')
in 6x 32 KBytes ROM
up to 320 KBytes ROM via external cartridge
TOS is also known as 'Tramiel Operating System', after Jack Tramiel (ATARI's boss these days). It's based on CP/M-68k, a MC68000 conversion of Gary Kildall's CP/M ('Control Program for Microcomputers'), adding a graphical user interface (GUI) similar to that of the Macintosh. Since both CP/M and GEM were products of Kildall's company Digital Research, Incorporated, it was easy to merge them and a clever decision. See the 520ST⁺ page for a GEM screenshot!
the last official TOS version was 4.04, used in the ATARI FALCON 030

Keyboard/ Layout Hitachi HD6301V1 (C070122, keyboard control)
95 keys/ german (QWERTZ) layout

Graphics C025914-38 'Shifter' (Video Shift Register Chip)
Resolutions:
320x200 ('LowRes', requires RGB-monitor/ TV)
640x200 ('MedRes', requires RGB-monitor/ TV)
640x400 ('HighRes', requires monochrome monitor)
Colors:
16 at 320x200 from 512 color palette
4 at 640x200 from 512 color palette
monochrome at 640x400
all 512 in LowRes with tricks possible

Text: 80x25 characters (although no 'real' text-mode)
PAL version; PAL or NTSC are detected via interrupt by the 68901. However, this is only interesting for LowRes and MedRes modes (50/ 60 Hz) - in HighRes, refresh is always 72 Hz
Upon operation, the ST's graphic subsystem takes 32 KBytes of RAM to utilize as 'BitMap video display memory'
Later machines (from 1040ST^FM on) used a 'BLiTTER' to speed up filling-operations (mainly to speed up GEM)

Sound Yamaha YM2149F
'Programmable Sound Generator'
3 independent voices, programmable volume; dynamic envelope shaping; wave shaping; programmable attack, decay, sustain, release; frequency range: 30 Hz to 125 KHz
built-in D/A converters
special: two MIDI IN and MIDI OUT ports controlled by the ACIAs

Media WD 1772-PH floppy-controller
C025913-38 DMA for floppy- and harddisk-access
up to 2 external drives using 3.5" disks with
360 KBytes/ disk (single-sided) or
720 KBytes/ disk (double-sided)
5.25" diskdrives, 360 KByte/ disk for PC-DD-compatibility
external harddisks at various sizes (e.g. ATARI Megafile)

Input/ Output 2x Motorola MC6850P ACIA ('Asynchchronous Communications Interface Adaptor')
National Semiconductor UA1488PC + UA1489APC (RS232)
Motorola 68901 'Multi-Function Peripheral'
Hitachi HD6301V1 (C070122, 1 MHz, basic-I/O and clock)
2x 9 pin SUB-D joystick/ mouse connectors
40 pin female edge conn. expansion bus
2x 5 pin round-DIN MIDI IN and OUT (31.25 KBaud)
13 pin round-DIN RGB monitor-out
25 pin SUB-D parallel
25 pin SUB-D serial (RS232C compliant, 19.2 KBaud max)
14 pin round-DIN external diskdrive-conn.
19 pin SUB-D for external harddisks
7 pin round conn. for external power supply
has a reset-button

Miscellaneous
The 260ST was sold with 512 KBytes RAM. That's because when the 520ST^M and 520ST⁺ appeared in Germany in 1986, the 'out-of-date' 520STs were rebadged as 260STs (like this one). But there were, however, two real 260ST prototypes, called 260STd and 260ST^FM, which featured 256 KB RAM and an integrated diskdrive (260STd: left (!) side, 260ST^FM right side, like all later machines). The 260ST^FM was, according to some sources, sold in very small quantities on european markets, and came with an integrated power supply (like the 1040ST^FM). The 260STd never made it into production... However, both machines' limited RAM size would have been insufficient for effective work with GEM (which was also ATARI's reason for mothballing the 130ST prototype)
In the very same year, the 520ST^M, 520ST⁺, 1040ST^F, 1040ST^FM and 520ST^FM were also released. The 1040STs and the 520ST⁺ featured 1 MByte RAM. Although the 520STs (except for the 520ST⁺) had 512 KBytes RAM, they were different machines: the 520ST^M and 520ST⁺ were based on the original 1985 520ST, whereas the 520ST^FM was simply a downgraded 1040ST^FM. All came with integrated floppies ('F') and/ or TV-modulators ('M')

'Nebulus' screenshot (25 KBytes) 'Super Sprint' screenshot (19 KBytes)

After it was succeeded by the 1 MB-STs, the 260ST was sold as a cheap entry-level machine and thus often used for gaming. Although it couldn't compete with Commodore's Amiga in graphics and sound, there've been many great games for it, like Hewson's 'Nebulus' (left, also known as 'Tower Toppler' in the UK), and Electric Dreams' 'Super Sprint' (right)

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Sothius' Home - Museum - ATARI - ATARI 260ST - additional pictures

Name	ATARI 260ST
Made by	ATARI Corp. Sunnyvale, California
Released	1986 first ST-prototypes were shown on CES 1985 (i.e. a 130ST with 128KB RAM) first ST officially sold was the 520ST (in Summer 1985)
Serial-No.	A1 4007726
Board-info	ATARI® C070243 Rev.C also see the board overview
CPU	Motorola MC68000 C025915-38 'GLUE' although having 16 bit data/ 24 bit address bus, the MC68000 internally processes 32 bits, thus the 'ST' (meaning 'sixteen thirtytwo') GLUE is the ST-architecture's 'Control logic' and coordinates all of its components
Speed	8 MHz
RAM	C025912-38 MMU 512 KBytes: 16 pcs. Texas Instruments TMS4256 (256Kx1) see 'Misc' for why it's nevertheless called 260ST expandable to 4096 KBytes, which is also MMU-limit
ROM/ Native OS	PAL TOS 1.0 ('The Operating System') in 6x 32 KBytes ROM up to 320 KBytes ROM via external cartridge TOS is also known as 'Tramiel Operating System', after Jack Tramiel (ATARI's boss these days). It's based on CP/M-68k, a MC68000 conversion of Gary Kildall's CP/M ('Control Program for Microcomputers'), adding a graphical user interface (GUI) similar to that of the Macintosh. Since both CP/M and GEM were products of Kildall's company Digital Research, Incorporated, it was easy to merge them and a clever decision. See the 520ST⁺ page for a GEM screenshot! the last official TOS version was 4.04, used in the ATARI FALCON 030
Keyboard/ Layout	Hitachi HD6301V1 (C070122, keyboard control) 95 keys/ german (QWERTZ) layout
Graphics	C025914-38 'Shifter' (Video Shift Register Chip) Resolutions: 320x200 ('LowRes', requires RGB-monitor/ TV) 640x200 ('MedRes', requires RGB-monitor/ TV) 640x400 ('HighRes', requires monochrome monitor) Colors: 16 at 320x200 from 512 color palette 4 at 640x200 from 512 color palette monochrome at 640x400 all 512 in LowRes with tricks possible Text: 80x25 characters (although no 'real' text-mode) PAL version; PAL or NTSC are detected via interrupt by the 68901. However, this is only interesting for LowRes and MedRes modes (50/ 60 Hz) - in HighRes, refresh is always 72 Hz Upon operation, the ST's graphic subsystem takes 32 KBytes of RAM to utilize as 'BitMap video display memory' Later machines (from 1040ST^FM on) used a 'BLiTTER' to speed up filling-operations (mainly to speed up GEM)
Sound	Yamaha YM2149F 'Programmable Sound Generator' 3 independent voices, programmable volume; dynamic envelope shaping; wave shaping; programmable attack, decay, sustain, release; frequency range: 30 Hz to 125 KHz built-in D/A converters special: two MIDI IN and MIDI OUT ports controlled by the ACIAs
Media	WD 1772-PH floppy-controller C025913-38 DMA for floppy- and harddisk-access up to 2 external drives using 3.5" disks with 360 KBytes/ disk (single-sided) or 720 KBytes/ disk (double-sided) 5.25" diskdrives, 360 KByte/ disk for PC-DD-compatibility external harddisks at various sizes (e.g. ATARI Megafile)
Input/ Output	2x Motorola MC6850P ACIA ('Asynchchronous Communications Interface Adaptor') National Semiconductor UA1488PC + UA1489APC (RS232) Motorola 68901 'Multi-Function Peripheral' Hitachi HD6301V1 (C070122, 1 MHz, basic-I/O and clock) 2x 9 pin SUB-D joystick/ mouse connectors 40 pin female edge conn. expansion bus 2x 5 pin round-DIN MIDI IN and OUT (31.25 KBaud) 13 pin round-DIN RGB monitor-out 25 pin SUB-D parallel 25 pin SUB-D serial (RS232C compliant, 19.2 KBaud max) 14 pin round-DIN external diskdrive-conn. 19 pin SUB-D for external harddisks 7 pin round conn. for external power supply has a reset-button
Miscellaneous	The 260ST was sold with 512 KBytes RAM. That's because when the 520ST^M and 520ST⁺ appeared in Germany in 1986, the 'out-of-date' 520STs were rebadged as 260STs (like this one). But there were, however, two real 260ST prototypes, called 260STd and 260ST^FM, which featured 256 KB RAM and an integrated diskdrive (260STd: left (!) side, 260ST^FM right side, like all later machines). The 260ST^FM was, according to some sources, sold in very small quantities on european markets, and came with an integrated power supply (like the 1040ST^FM). The 260STd never made it into production... However, both machines' limited RAM size would have been insufficient for effective work with GEM (which was also ATARI's reason for mothballing the 130ST prototype) In the very same year, the 520ST^M, 520ST⁺, 1040ST^F, 1040ST^FM and 520ST^FM were also released. The 1040STs and the 520ST⁺ featured 1 MByte RAM. Although the 520STs (except for the 520ST⁺) had 512 KBytes RAM, they were different machines: the 520ST^M and 520ST⁺ were based on the original 1985 520ST, whereas the 520ST^FM was simply a downgraded 1040ST^FM. All came with integrated floppies ('F') and/ or TV-modulators ('M')


After it was succeeded by the 1 MB-STs, the 260ST was sold as a cheap entry-level machine and thus often used for gaming. Although it couldn't compete with Commodore's Amiga in graphics and sound, there've been many great games for it, like Hewson's 'Nebulus' (left, also known as 'Tower Toppler' in the UK), and Electric Dreams' 'Super Sprint' (right)